016. Optics (Electromagnetics)
This problem asks for the application of Fermat’s principle of ray optics to other optics laws.
This principle shows the path of the light, so it can also be used to explain reflection and refraction of the light. So we can derive Snell’s law and the law of reflection from Fermat’s principle. Rayleigh’s criterion for resolution, however, cannot be explained by this principle. It can be derived from the diffraction.